The "staling" of bread, cakes and other bakery products is commonly believed to be the result of natural chemical and physical changes which occur in the finished baked product upon storage under normal conditions. The mechanisms and contributing factors for those chemical and physical changes are known to be complex and varied. As a result, not all the mechanisms and contributing factors are yet fully understood. However, the commonly accepted primary cause of crumb firming among cereal chemists is the retrogradation or recrystallization of the components of starch, amylose and/or amylopectin after gelatinization. (See Knightly, "The Staling of Bread", Bakers Digest, Vol. 51, No. 5, pp. 52-56, 144-150 (1977)). Whatever the cause of "staling", it is known that its onset is quite fast following baking unless retarded by certain antistaling additives. Indeed, under certain accepted definitions, bread baked without known antistaling additives could be considered as stale bread after only a matter of a few hours following baking.
Antistaling agents normally used in the production of breads, cakes and other bakery products include monoglycerides and mixtures of monoglycerides with diglycerides, U.S. Pat. No. 3,547,655 discloses an improved antistaling agent which is a combination of monoglycerides and a synthetic polyethoxylated derivative of a fatty acid ester of a hexitol, hexitan or an isohexide.
U.S. Pat. Nos. 369,907 and 3,485,639 disclose an antistaling/mold inhibiting agent which is a combination of monoglycerides with a synthetic lower monocarboxylic acid ester of a polyhydric alcohol.
U.S Pat. No. 3,394,009 discloses a synthetic ester of glycerine and a lower carboxylic acid such as propionic acid as an antistaling agent for bakery products.